Tamper proof closure



Sept. 28, 1965 M. R. FIELDS 3,208,649

TAMPER PROOF CLOSURE Filed Aug. 1, 1961 2 Sheets-Sheet l Sept. 28, 1965 M. R. FIELDS 3,208,649

TAMPER PROOF CLOSURE Filed Aug. 1, 1961 2 Sheets-Sheet 2 F' 'g H INVENTO MACK I2. F/e

United States Patent 3,208,649 TAMPER PROOF CLOSURE Mack R. Fields, Libertyville, Ill., assignor to Roehr Products Company, Inc., Deland, Fla., a corporation of Delaware Filed Aug. 1, 1961, Ser. No. 128,403 18 Claims. (Cl. 222541) This invention relates to container closures and methods of making same, and, more particularly,- to a closure cap of the so-called tamper proof type.

One common type of tamper-proof closure currently in use consists of a sheet metal cap having a depending side wall which is in screw threaded engagement with the threaded neck of a glass bottle or the like. On the sidewall of the cap below the thread is a skirt which surrounds the bead on the bottle below the threaded neck thereof, and the skirt is turned inwardly to grip the bottom surface of the bead. At the juncture of .the skirt and side wall, the cap is formed with a circumferential score line where the metal is sheared through except for several equally spaced points where bridges of the metal join the side wall to the skirt. When the cap is initially unscrewed from the bottle, the skirt is retained against upward movement with the result that the bridges of metal fracture, separating the skirt from the rest of the cap. Thus, separation of the skirt from the rest of the cap will indicate that the cap has been previously removed or that there has been tampering with the cap.

Closures of this type are often supplied by the cap maker to the user with the score line formed but with an unthreaded side wall. When the user caps the bottle, the unthreaded caps are first telescoped over the threaded bottle neck whereupon rollers deform the cap side wall and impress a thread thereon into the thread on the bottle neck. At the same time, the skirt is turned under and against the bead on the bottle.

These closures sometimes have an unattractive appearance as a result of the irregular external contours formed during the roll-threading operation. Furthermore, after the skirt has been severed from the side wall, the raw edge of metal remaining on the cap side wall is exposed and may result in injury to persons subsequently handling the closure. Moreover, in the prior art, the skirt, with its raw edge exposed, remains secure on the bottle.

It is an object of the present invention to provide a tamper-proof closure in which substantially the entire raw edge of metal remaining on the cap is covered by a plastic outer shell or covering which surrounds the metal of the cap.

It is also an object of the present invention to provide a closure of the type stated in which the severed skirt may be readily removed from the container bead without the use of a cutting tool or other suitable instrument.

It is a further object of the present invention to provide a closure of the type stated in combination with a container having a threaded neck so as to form a readily openable yet pilfer-indicating structure.

It is another object of the present invention to provide a closure of the type stated in which the plastic coating is molded over the metal of the side wall while at the same time forming a thread on the side wall of the cap.

It is an additional object of the present invention to provide a closure in which a part of the end wall of the cap projects through the plastic shell in a predetermined configuration to present to view the metal of the cap in said configuration against a background of the plastic. The configuration may be any suitable indicia, such as letters, numerals, trademarks, or the like, and may be of a contrasting color with that of the plastic.

3,208,649 Patented Sept. 28, 1965 ICC t is a still further object of the present invention to provide a method of making a closure having an inner cap member and an outer plastic shell in a manner to form a raised indicia of cap material against a contrasting background of plastic material.

The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawing forming a part thereof.

In the drawing:

FIG. 1 is a fragmentary sectional view showing apparatus and a step in the process of making a closure in accordance with the present invention;

FIG. 2 is a fragmentary sectional view taken along line 22 of FIG. 1;

FIG. 3 is a fragmentary sectional view, on an enlarged scale, of a portion of FIG. 1 and showing one of the mold members of the present invention just prior to being shifted to its operative or mold-forming position;

FIG. 4 is a fragmentary sectional view similar to FIG. 3 and showing the mold member in its final position before the injection of plastic into the mold;

FIG. 5 is a fragmentary sectional view, on an enlarged scale, of another portion of the apparatus of FIG. 1;

FIG. 6 is a fragmentary sectional view similar to FIG. 1 after the plastic has been injected into the mold;

FIG. 7 is a top plan view of a completed closure constructed in accordance with the present invention;

FIGS. 8 and 9 are fragmentary sectional views, each on an enlarged scale, taken along lines 88 and 99 respectively, of FIG. 7;

FIGS. 10 and 11 are fragmentary sectional views taken along lines 10-10 and 11-11 of FIG. 9;

FIG. 12 is a sectional view of the closure through the axis thereof and showing the closure threaded on to the neck of a container;

FIG. 13 is a fragmentary sectional view taken along line 1313 of FIG. 12;

FIG. 14 is a sectional view similar to FIG. 12 and showing the closure partially unscrewed from the neck of a container; and

FIG. 15 is a fragmentary sectional view, on an enlarged scale, of a portion of the structure shown in FIG. 14.

Referring now in more detail and by reference numerals to the drawing, which illustrates a preferred embodiment of the present invention, 1 designates a hollow member such as a cap blank or shell which may be drawn from any suitable sheet metal, such as light gauge aluminum or tin plate and may, for example, have a wall thickness of approximately .008 to .010 inch. The cap blank 1 includes an upper end wall 2 and an unthreaded cylindrical depending side wall 3. At the open end of the cap blank 1 is a cylindrical skirt 5 having a diameter greater than that of the side wall 3. A radially outwardly extending shoulder 6 provides a juncture between the lower end of the side wall 3 and the upper end of the skirt 5. The shoulder 6 includes a circumferentially extending zone of weakness which is formed by severing the metal of the shoulder except at a plurality of narrow bridges 8 which provides the integral connection between the side wall 3 and skirt 5. The bridges 8 are preferably equally spaced and may, for example, be of the order of of an inch wide. In the score-through or severing operation of the shoulder 6, the radially outermost part 9 (FIG. 5) of the shoulder 6 is bent downwardly of the radially innermost part 10 so that the raw edges 12, 13 at the -severence will be offset from each other with the edge 12 above the edge 13. It will be apparent that the edges 12, 13 are continuous with the side wall 3 and skirt 5, respectively.

Apparatus 15 is provided for threading the side wall 3, applying a plastic coating to the side wall 3 and Wall 2, and forming an indicia on the top wall 2 with a contrasting background of plastic. The apparatus 15 comprises a mold member 16 having a mold cavity 18 and one or more mold gates 19 through which plastic may be introduced into the mold cavity 18. At its open end the mold member 16 is diametrally enlarged to receive the skirt 5, and the inner end or base of the enlargement 20 provides a radial shoulder 21 which seats against the outer part 9 forming a seal against the flow of plastic around the outside of the skirt 5. Telescoped into the skirt is a shut-off backing or sealing ring 22, the upper end of which is shaped to receive the shoulder 6 and support or back the latter, enabling the shoulder 21 to bear firmly and sealing-wise against the outer part 9. Surrounding the sealing ring 22 is a stripper plate 24 which is adapted to engage the lower end of the skirt 5 to strip the completed closure from the mold, as will be presently more fully explained.

A tubular, collapsible core collet or die 25 projects through the sealing ring 22 and terminates in a helical thread 26 which corresponds to the thread on the glass bottle or other container upon which the closure is to be threaded. The die 25 is of resilient metal and longitudinally slotted to provide a plurality of sections 27 and is preferably of the type shown in my United States Patent No. 3,125,801 that issued March 24, 1964, to which reference may be had. For supporting the die 25 in its thread-forming position a center pin 28 is provided, and the center pin 28 may be axially shifted out of supporting engagement with the threaded part 26 of the die 25 to allow said threaded part to collapse in the manner set forth in said co-pending application.

The end surface 29 of the center pin 28 has a raised rib 30 in the shape of a desired indicia to be presented to view at the top of the completed closure. As shown in FIG. 2, the rib 30 is in the shape of the letter U, although it will be apparent that other letters, numbers, trademarks, designs, and other indicia, as desired, may be used. By way of example, but not of limitation, it has been found that for a blank having a wall thickness of from .008 to .010, the height of the rib 30 may be approximately .060 inch, while the width of the rib 30 at its top surface 32 should be approximately .064 inch. The cavity wall 33 of the mold member 16 is undercut in the order of .008 inch to provide a recess 34 in the configuration of the indicia. The recess 34 may have a width at the face 33 of approximately .080 inch.

FIG. 3 shows the relative positions of the rib 30, mold member 16, and wall 2 just prior to the mold member 16 being shifted to its operative or mold forming position while FIG. 4 shows the same parts when the mold member 16 is in its mold forming position. It will be noted from FIG. 4 that the metal of the wall 2 is deformed into the recess 34, filling the latter, and is held tightly therein by the cooperation of the rib 30 and the mold member 16.

When a suitable plastic, such as polystyrene, is injected into the mold cavity 18 under pressure through the mold gates 19, the plastic will deform the metal of the side wall 3 into the die thread 26 and form a thread 36 on the side wall 3. The pressure of the plastic likewise deforms the metal of the wall 2 against the rib 30, end 29, and the end of the die 25. The plastic extends to the shoulder 6 and covers the radially outwardly presented edge 12 and the lateral edges of the bridges 8, as shown in FIGS. 9-11, but does not flow around the skirt 5 due to the seal at the shoulder 21. When hardened, the plastic forms a shell 39 having an end wall 40 and side wall 41 with an indicia portion 42 of the wall 2 projecting through the end wall 40. As best seen in FIG. 8, the end wall 40 of the plastic coating or shell 39 will be of a height slightly less than the height of the rib or raised projection 42 on the cap end wall 2 due to the fact that the metal of the top wall fills the recess 34 and the face 33 is below the base of the recess 34. In the present embodiment, this difference in height is approximately .008 inch with the result that the upper surface of the indicia-projection 42 is raised upwardly from the shell top wall 40 approximately .008 inch.

To remove the completed closure C from the mold, the mold member 16 is axially withdrawn past the closed end of the closure C and the center pin 28 is axially retracted from supporting engagement with the die 25. The stripper plate 24 may then eject the closure C from the die 25, the latter radially contracting a sufiicient amount to permit the closure thread 36 to clear the die thread 26. Thereafter, a conventional wax impregnated sealing disk 44 may be inserted into the closure C to underlie the end wall 2. The periphery of the sealing disk 44 is held in an internal annular groove 45 between the cap end wall 2 and an annular shoulder 45' that is formed in the side wall 3 during the molding and the shell forming operations by reason of the fact that the top peripheral portion of the die 24 holds the adjacent part of the side wall 3 of the cap blank 1 to a diameter substantially equal to its initial diameter, which is greater than the internal diameter of the thread that is being formed therebelow.

FIGS. 12 and 13 show the closure threaded onto a container. The container may be a bottle 46 having a neck 47 which constitutes a pour-out opening for the bottle. The neck 47 has a thread 49 which matches the closure thread 36. Immediately below the bottle thread 49 the neck 47 is integrally provided with a head 51 larger in diameter than the bottle thread 49 but smaller than the inside diameter of the skirt 5. The head 51 has a plurality of circumferentially spaced, radially outwardly opening recesses 53. As best seen from FIG. 12, when the closure C is threaded on to the neck 47 such that the sealing disk 44 is tightly pressed against the upper end of the neck 47, the shoulder 6 lies just above the bottle bead 51 and the skirt 5 encircles the bead 51. A suitable tool may then deform portions 55 of the skirt 5 into the recesses 53 to secure the skirt 5 against rotation relative to the bottle 46.

When the cap is initially unscrewed by applying a counterclockwise twisting torque thereto, the bridges 8 will fracture leaving the skirt 5 in place, as shown in FIG. 14. The main part of the closure may then be removed from the bottle neck whereupon the skirt 5 may be lifted up axially over the bottle neck 47 and then discarded. The closure C is thereafter used as an ordinary cap. It will be apparent that if the skirt 5 is severed from the remainder of the closure C, this fact will indicate that the closure has been previously removed or that there has been tampering with the closure.

As seen from FIG. 15, the plastic of the side wall 41 of the shell 40 continues to cover the radially outwardly presented raw edge 12 after fracture of the skirt 5 except at the break lines of the narrow bridges 8 which constitutes only a very small fraction of the zone of weakness. This shielding of the raw edge 12 reduces the possibility of a raw edge of metal cutting the hand of a person handling the closure.

In compliance with the requirements of the patent statutes 1 have herein shown and described a preferred embodiment of the invention. It is, however, to be un derstood that the invention is not limited to the precise construction herein shown, the same being merely illustrative of the principles of the invention. What is considered new and sought to be secured by Letters Patent is:

1. A closure comprising an inner hollow member having an open end and a threaded wall terminating in a skirt lying radially outwardly of the wall and defining said open end, said member having a radial shoulder joining the bottom of the wall with the top of the skirt, means forming a fracturable zone of weakness on the member between said open end and threaded wall, a' plastic shell having a wall surrounding the threaded wall, cooperating means on the shell and member for nonrotatably and non-removably securing the shell to the member, the wall of the shell extending along the Wall of the member at least to the radial shoulder.

2. A closure comprising a hollow member open at one end and having a threaded annular wall terminating in a skirt which defines said open end, said member having an annular fracturable zone of weakness at the juncture of the skirt and threaded wall, said zone of weakness including portions where the material of the member is severed, and a plastic shell secured to the member and having an annular wall surrounding the threaded wall in close-fitting relation-thereto, the shell wall extending axially along the member wall at least to the severed portions and covering the edge of member material that is contiguous with the member wall.

3. A closure comprising a hollow member having a threaded annular wall terminating in an annular skirt which defines an open end of the closure, said member including a radially outwardly projecting shoulder constituting the region of the juncture of the skirt and threaded wall, the shoulder having means forming an annular zone of weakness at which the skirt may be separatedfrom the remainder of the closure upon fracture thereat, and a plastic shell secured to the member and having an annular wall surrounding the threaded wall in close-fitting relation thereto and extending axially to said shoulder in overlying relation to said zone of weakness with at least a part of the shell wall at said shoulder being radially outwardly of the zone of weakness.

4. A closure comprising a hollow member having a threaded annular wall, an annular skirt joined to said wall and terminating in an axially extending annular flange which defines an open end of the closure, the juncture of the skirt and said Wall including a radially outwardly projecting shoulder having an annular zone of weakness at which the closure may be separated into two parts upon fracture thereat, and a plastic shell molded in situ over the member and having an annular wall surrounding the threaded wall in close-fitting relation thereto and terminating at said shoulder with at least a portion of said shell wall at said shoulder being radially outwardly of the zone of weakness.

5. A closure comprising a hollow member open at one end and having a threaded annular wall terminating in a skirt which defines said open end, said member having an annular fractu-rable zone of weakness at the juncture of the skirt and threaded wall, the zone of weakness being formed by a plurality of circumferentially spaced regions at which the member material is severed with said regions being separated by narrow bridges of the member material which form a connection between the skirt and member wall, the edge of material at the severance that is contiguous with the member wall being offset from the edge of material that is continuous with the skirt, and a plastic shell permanently secured to the member and having an annular wall surrounding the threaded wall in close-fitting relation thereto, the shell wall extending axially along the member at least to the zone of weakness with the plastic covering said edge that is continuous with the member wall.

6. A closure according to claim 5 wherein the plastic shell is molded in situ over the member.

7. A closure comprising a hollow member open at one end and having a threaded annular wall terminating in an annular axially extending skirt which defines an open end of the closure, said member integrally including a radially outwardly projecting shoulder constituting the region of juncture of the skirt and threaded wall, said shoulder having a plurality of circumferentially spaced regions at which the member material is severed to form radially inwardly and outwardly presented raw edges of material which are offset from each other, said regions being separated by narrow bridges of member material which provide a connection between the skirt and member wall, and a plastic shell permanently secured to the member and having an annular wall surrounding the threaded wall in close-fitting relation thereto, the shell wall extending axially along the member to the shoulder with the plastic covering the radially outwardly presented edge of member material, whereby upon fracture of said zone of weakness, said radially outwardly presented edge will remain shielded by the plastic shell.

8. In combination with a container having a threaded neck constituting a pour-out opening, a closure for the filling opening, said closure comprising a hollow member having a threaded wall surrounding the neck and with the threads of the wall in engagement with the threads of the neck, a skirt at one end of the wall and projecting axially therefrom, means forming a zone of weakness at the juncture of the skirt with the member wall, a plastic shell having a wall surrounding the threaded member wall and extending along the threaded wall at least to the zone of weakness, means locking the shell to the member against axial movement with respect thereto, said skirt having a part thereof cooperating with said container so that upon application of an unscrewing twisting torque to said closure, the cooperation of the container and skirt part will retain the skirt against rotation and the member will fracture along the zone of weakness.

9. In combination with a container having a threaded neck constituting a pour-out opening, said container having an annular bead axially spaced from the threaded portion of the neck, a closure for the filling opening, said closure comprising a hollow member having a threaded wall surounding the neck and with the threads of the wall in engagement with the threads of the neck, a skirt at one end of the wall and projecting axially therefrom and surrounding the bead, means forming a zone of weakness between the lower end of the skirt and the member wall, a plastic shell having a Wall surrounding the threaded member wall extending axially to said zone of weakness, means locking the shell to the member against axial movement with respect thereto, said skirt having a part thereof radially deformed into interference with said bead after the member has been threaded onto the threaded neck so that upon application of an unscrewing twisting torque to said closure, the cooperation of the bead and deformed part of the skirt will retain the skirt against movement such that the member will fracture along the zone of weakness and the plastic will shield the raw edge of material remaining on the member.

10. In combination with a container having a threaded neck constituting a pour-out opening, said container having an annular bead axially spaced from the threaded portion of the neck, a closure for the filling opening, said closure comprising a hollow member having a threaded wall surrounding the neck and with the threads of the Wall in engagement with the threads of the neck, a skirt at one end of the wall and projecting axially therefrom and surrounding the bead, means forming a zone of Weakness at the juncture of the skirt with the threaded member wall, said means including portions where the material of the member is severed to provide adjacent edges continuous with the member wall and skirt respectively, a plastic shell having a wall surrounding the threaded member wall and extending axially therealong at least to the zone of weakness and covering the edge of member material that is contiguous with the member wall, means locking the shell to the member against axial movement with respect thereto, said skirt having a part thereof cooperating with the bead so that upon application of an unscrewing twisting torque to said closure, said cooperating parts will retain the skirt against rotation and the member will fracture along the zone of weakness.

11. In combination with a container having-a threaded neck constituting a pour-out opening, and said container having an annular bead axially spaced from the threaded portion of the neck and at least one outwardly opening recess in thebead, a closure for the filling opening, said closure comprising a hollow member having a threaded wall surrounding the neck and with the threads of the Wall in engagement with the threads of the neck, a skirt at one endof the wall and projecting axially therefrom and surrounding the bead, means forming a zone of weakness at the juncture of the skirt with the member wall, said means including a plurality of circumferen- .tially spaced regions at which the member material is severed to form adjacent edges of member material contiguous with the threaded wall and skirt respectively, said regions being separated by narrow bridges of member material which form a connection between the threaded wall and skirt, a plastic shell having a wall surrounding the threaded member wall in close fitting relation thereto and extending axially therealong at least to the regions of severance and covering said edge of member material that is continuous with the threaded wall, means locking the shell to the member against axial movement with respect thereto, said skirt having a part' thereof projecting into said recess so that upon application of an unscrewing twisting torque to said closure, the cooperation of the bead and skirt part deformed therein will retain the skirt against rotation and the member will fracture along the zone of weakness.

12. A closure comprising a cap open at one end and having an end wall at its other end, said cap having a threaded side wall for threading over the neck of a container, a shell over said cap and having a side wall surrounding the threaded wall of the cap, means for securing the shell against axial retraction from the cap, a part of the end wall of the cap that is integral with the side wall projecting through the shell end wall and said projected part of the cap end wall being in the configuration of indicia, and the end wall of the shell being imperforate except where said projected part projects therethrough.

13. A closure comprising a cap open at one end and having an end wall at its other end, said cap having a threaded annular Wall for threading over the neck of a container, a plastic coating molded in situ over the end wall of the cap, said end wall of the cap having a raised portion integral with the side wall and in the configuraration of indicia and projecting through the plastic coating with the plastic coating being contiguous with the raised portion to present to view the indicia against a background of the plastic.

14. A closure comprising a shell open at one end, said closure having an end wall opposite the open end of the shell, said shell having a threaded annular side wall for threading over the neck of a container, a radially projecting first shoulder formed in said annular side wall intermediate the thread and end wall and spaced from said end wall, a radially projecting second shoulder intermediate the thread and open end and a plastic coating molded in situ over the exterior of the threaded side wall, said second shoulder terminating in means for restraining longitudinal retraction of the closure from the neck of the container, the second shoulder having a weakened line of fracture between said last named means and said threaded wall, and said plastic coating extending at least to said weakened line of fracture.

15. A closure comprising a hollow member having a threaded side wall that terminates at its lower end in means forming an open lower end of the member, said member having an annular fracturable zone of weakness above said open end and at which the member may be fractured into a plurality of parts that leave a-raw edge of material on the member, a plastic shell on said side wall, in close-fitting surrounding relation thereto, and cooperating means on the shell and member for permanently securing the two together, said shell extending axially along said side wall at least to the zone of weakness so that upon fracture of the member at said zone of weakness, the raw edge of material remaining on the member will be shielded by the plastic. I

16. A closure comprising a hollow member having a threaded annular side wall for threading over the threaded neck of a container, the sidewall terminating at its lower end in an axially extending skirt defining an open end of the closure, means forming an annular zone of weakness on the member intermediate said open end and side wall and at which the member may be fractured into a plurality of parts, a plastic shell surrounding the side wall in close-fitting relation thereto, and cooperating means on the shell and member for permanently securing the two together.

17. A closure comprising a hollow member having a threaded annular side wall for threading over the threaded neck of a container, the side wall terminating in a skirt that defines an open end of the closure, shoulderforming means projecting radially outwardly from the adjacent end of the side wall and constituting the juncture of the skirt and the threaded wall, means forming an annular zone of weakness on the member intermediate said open end and said side wall at which the closure may be separated into a plurality of parts upon fracture thereat, a plastic shell surrounding the side wall in close-fitting relation thereto and extending axially therealong to said shoulder-forming means, and cooperating means on the shell and member for permanently securing the two together.

18. A closure comprising a hollow member having a threaded annular depending side wall for disposition threading over the threaded neck of a container, the side wall terminating in an axially extending skirt joined to the adjacent end of said side wall and defining an open axial end of the closure, shoulder-forming means projecting radially outwardly from said adjacent end of the side wall and constituting the juncture of the skirt and the threaded wall, means forming an annular zone of weakness on the member intermediate said open end and said side wall at which the closure may be separated into a plurality of parts upon fracture thereat, said zone of weakness being formed by a plurality of circumferentially spaced regions at which the member material is severed with the regions being separated by narrow bridges of member material which form a connection between the adjacent parts of the cap, a plastic shell surrounding the side Wall in close fitting relation thereto and extending axially thereof to said shoulder-forming means, and cooperating means on the shell and member for permanently securing the two together.

References Cited by the Examiner UNITED STATES PATENTS 1,360,388 11/20 Gaynor.

1,589,913 6/26 Wells.

2,033,643 3/36 Neill 18-59 2,158,044 5/39 Haller 1859 2,162,712 6/39 Hamberger 215-7 2,173,449 9/39 Kronman 21543 2,684,502 7/54 Paulve.

3,025,988 3/62 Williams 21542 X 3,025,989 3/62 Williams 215-42 X RAPHAEL M. LUPO, Primary Examiner, 

15. A CLOSURE COMPRISING A HOLLOW MEMBER HAVING A THREADED SIDE WALL THAT TERMINATES AT ITS LOWER END IN MEANS FORMING AN OPEN LOWER END OF THE MEMBER, SAID MEMBER HAVING AN ANNULAR FACTURABLE ZONE OF WEAKNESS ABOVE SAID OPEN END AND AT WHICH THE MEMBER MAY BE FRACTURED INTO A PLURALITY OF PARTS THAT LEAVE A RAW EDGE OF MATERIAL ON THE MEMBER, A PLASTIC SHELL ON SAID SIDE WALL IN CLOSE-FITTING SURROUNDING RELATION THERETO, AND COOPERATING MEANS ON THE SHELL AND MEMBER FOR PERMANENTLY SECURING THE TWO TOGETHER, SAID SHELL EXTENDING AXIALLY ALOND SAID SIDE WALL AT LEAST TO THE ZONE OF WEAKNESS SO THAT UPON FRACTURE OF THE MEMBER AT SAID ZONE OF WEAKNESS, THE RAW EDGE OF MATERIAL REMAINING ON THE MEMBER WILL BE SHIELDED BY THE PLASTIC. 